Britain's King Charles III spent a second day in hospital on Saturday where he was visited by his wife Queen Camilla following scheduled prostate surgery.

Camilla was seen arriving by a back entrance at the London Clinic, a private hospital in the capital, where he underwent the procedure on Friday.

Charles's daughter-in-law Catherine Princess of Wales, 42, is currently also at the hospital where she has spent 12 days following abdominal surgery.

Reports have said Charles, 75, was expected to spend two days in hospital and that he was "doing well" after the surgery.

Royal officials took the unusual step last week of issuing a bulletin on the king's health, disclosing that he had an enlarged prostate but the condition was benign.